Mr. Broderip and Mr. G. B. Sowerby on Mollusoa. 49 
pearance of a Mactra, that it might at first sight be easily mistaken for 
one. In form it is triangular, nearly equilateral, and somewhat de- 
pressed; its base and lower angles are rounded ; it is of a pale yellowish 
colour, with many diverging fuscous rays: within it is white, varied with 
brownish violet, and its posterior cardinal tooth is unusually remote. 
VENUS DECORATA. 
[Tas. Supp. xu. f. 3.] 
V.. testd cordato-trigond, latere postico productiore, albd, liris longt- 
tudinalibus crenulatis sulcisque radiantibus decussatis granulosd, 
margine crenulato. 
Habitat ? 
This highly decorated shell (the only specimen we have seen) bears 
some resemblance in its outward ornament to Arca gradata. It was 
brought home in the Blossom. In Mr. Sowerby’s collection. 
BULINUS BILABIATUS. 
[Tas. Supe. xu. f. 1, 2.] 
B. testd acuminato-ovali, anfractibus 5, (ultimo ad basin angulato) 
costis elevatis obliquis distantibus, pallide fuscd ; aperturd auricu- 
lari, peristomate reflexo, sinuoso, pone labium lamellifero ; colu- 
melld obtuse uniplicata. 
Hab. in Brasilia. 
We have placed this extraordinary shell under the genus Bulinus, 
being unwilling to add to the list of generic names till we are compelled 
todoso. But the species is so intermediate in its character between the 
Auricule and the Bulini, that it might be referred to either with little 
violence. The mouth of the shell, as well as its general appearance, 
is unlike that of any of the Testacea which we have seen. Ata little 
distance behind the reflected lip rises a shelly plate, which in an earlier 
state of its existence appears to have formed the right side of the aper- 
ture. We have only seen two specimens; but both of these have the 
same formation which does not seem to be accidental. In the collections 
of Mr. Bland and Mr. Sowerby. 
Both specimens appear to have suffered by exposure to the weather. 
Vou. V. D 
